Filtering and dehydrating device for the refrigerant in mechanical refrigerators



Feb. 28, 1939. w. R. MITTENDORF 2,143,770

FILTERTL-NG AND DEHYDRATING DEVICE FOR THE REFRIGERANT IN MECHANICAL REFRIGERATORS I Filed Sept. 18, 1935 INVENTOR. MLL/AM'R M/ 7'7'E/V00/PE ATTORNEYS.

Patented Feb. 28, 1939 FILTERING AND FOR THE REFRIGERANT 1N REFRIGERATORS DEHYDRATING DEVICE MECHANICAL William R, Mittendori, Cincinnati, omo, assignor to The Orosley Corporation, Ohio, a corporation of Ohio Cincinnati,

Application September 18, 1935, Serial No. 41,105 I 4 Claims. "(c 210- -131)- generally cylindrical form, and having two por- My invention has to do with mechanical refrigerators, and its primary object is to provide a device for removing impurities, foreign matter and/or moisture, from the refrigerant stream. It is well known that moisture in a mechanical refrigerating system is highly disadvantageous in that it becomes entrained in the stream of refrigerant passing therewith through various portions of the apparatus, until it reaches a low temperature portion, whereupon the moisture freezes into ice, and either clogs small passages or forms dead spots in the evaporator. As a consequence, elaborate procedures are ordinarily taken to eliminate moisture from the apparatus, both in setting up new refrigeration devices and in repairing those already in use, where such repairing requires a disassembly of the parts.

Again, mechanical impurities or foreign matter in the refrigerant stream are a source. of consid-,

erable trouble in all types of refrigeration apparatus, but especially in those types employing a flooded evaporator which is continuously fed by a moisture from the refrigeration stream, and

which device may be located aheadof the evaporator so as to keep any moisture in the system on the high pressure side of the apparatus.

It is an object of my ,invention'to provide a combined filter and dehydrator which is small in size, and which, without alteration of the design or construction of other parts of "the refrigerating apparatus, may be combined with new or existing machines.

' These and other objects of my invention which will be set forth hereinafter, or will be apparent to one skilled in the art upon reading these specifications, I accomplish by that certain construction and arrangemert of parts of vhich I shall now describe a' preferred embodiment. Reference is made to the drawin wherein:

Figure l is an exterior plan view of my device, and Fig. 2 is a sectional view thereof taken along the axis.

In the exemplary and preferred embodiment of my invention T provide a casing or body I of moisture,

tions 2 and 3 of different diameters so that a shoulder 4 is provided therebetween. This casing may be made of drawn or stamped sheet metal. An entrance fitting is provided as shown at 5, which fitting may be brazed or welded, or

otherwise attached to the casing, or, of course, formed integral therewith. The fitting is perforated as at 6 for the passing of refrigerant. The fitting may preferably be of any of those well-known types whereby flexible metallic tubing is connected to other apparatus. In the figures, the entrance tubing'is shown at I, preferably a tinned copper tubing, either, attached to or forming a part of the condenser of the re- 'frigerator apparatus, Where the condenser is formed of one or more tubes formed into convolutions and provided with fins, the end of such tubing may be attached directly to: the fitting 5.

I have shown a'type of fitting in which-a memher 8 is placed about the tubing, the tubing flared as at 9', and'the memberia then screwedtightly into'the fltting 5. I I

As I have illustrated my exemplary embodiment, a portion of the fitting 5 extends into the casing l.- Over this extensionv I place a" screen member HL- By reason of the projection of the fitting 5, this screen'member'may conveniently be of cup-shape, so' as'to hold itself in place in the casing. Other equivalent constructions are within the province of the skilled worker to devise.

Into the reduced portion 2, of the casing, 1

place a quantity of moisture-removing substance as shown at H. 'I'hereare several materials which can be employed for this purpose. Any

hygroscopic salt whichIis-inert to the refrigerant or metal parts, and which is not adapted to liquefy upon the absorption of small quantities of may be employed. Thus calcium chloride is a materialwhich will be found satisfactory. Since the quantity of moisture which will be found in refrigerating apparatus upon assembly, or which will get into it when repairs are made is comparatively small, and since the refrigerating apparatus operates as a closed system so that additional moisture does not enter it from time to time, I prefer to use some form of absorbent material for the moisture which has no tendency to become dissolved therein. For this purpose there are also a number of materials which can be used. I prefer to use activated alumina.

A screen member I! is next placed in the casing, being of a size to rest upon the shoulder 4.

'Next a spacing ring 13 is placed on the screen.

Additional screen members II and I5 may be employed if desired, each preferably being spaced from the other and/or surmounted ,by spacing rings l6, l1, and etc. The screen used is a fine mesh screen, having about sixty meshes to the linear inch in some instances, and as many as other mechanical impurities, or other foreign substances which may be entrained in the refrigerant stream.

When as many or the screen members have been placed in the casing as desired, I place in the casing a cap or closure member indicated at l8, preferably one having a peripheral fiange Hi. This cap or closure member may be fastened to the casing again in any way desired, but I have found it most convenient to close the casing by welding the flange ll of the closure member to the edge of the container or housing, electrically or by the use of a flame.'

The closure member is perforated to receive an outlet tube. I have shown as an outlet tube a capillary tube 20. which may be carried direct to the evaporator of a refrigerator. This capillary tube preferably projects a slight distance through the cap or closure member as shown in Fig. 2 at 200. The purpose of this is to prevent any mechanical impurities which may possibly pass the screens from being swept into the capillary tube. The cap or closure is provided with a. fitting for making a liquid tight seal with the outlet tube, One such fitting illustrated comprises an internally and. externally threaded hollow boss or sleeve 2|, which may be integral with the cap member I, but which is preferably formed with a reduced portion 21a projecting through, and closely fitting within a central bore in the cap member I8. A collar lib is welded or otherwise solidly fastened to the reduced portion 2 la on the other side of the cap member I8, to hold the assembly in fixed and leakprooi relation with said cap member. The external threads on the member 2| are for purposes of attachment to other portions of a refrigerator. A resilient compressible and expansible packing means 22 is placed withir; the sleeve and about the tube, whereupon a threaded member.23 is threaded into the sleeve to compress the packing about the tube, to hold it solidly in place and to make a liquid-tight connection.

Modifications may be made in my invention without departing from the spirit thereof.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is:-

1. In combination in a device of the character described, a cylindrical housing having portions of varying diameters, leaving a shoulder therebetween, an entrance fitting in the portion of the of at least two diflferent diameters, comprising in the order named, an entrance fitting, a screen covering said fitting, a filling of hygroscopic filtering material, said fitting, screen and filling being located in the smaller portion, a second screen to retain said filling in place, at least one -fine mesh screen spaced from said last mentioned screen, said second screen and said fine mesh screen being located in the larger portion, and a cover member provided with an exit fitting.

3. In a device of the character described, a substantially cylindrical housing having portions of at least two different diameters, comprising in the order named, an entrance fitting, a, screen covering said fitting, a filling of'hygroscopic filtering material, said. fitting, screen and filling being located in the smaller portion, a second screen to retain said filling in place, a plurality of interspaced fine mesh screens spaced from said last mentioned screen, said second screen and said plurality of fine mesh screens being located in the larger portion, and a cover member spaced from the last of said fine mesh screens and provided with an exit fitting.

. 4. In combination in a device of the character described, a cylindrical housing having portions of different diameters, leaving a shoulder therebetween, tube fittings in each end of said housing, a screen in the smaller portion of said housing covering said fitting, a filling of hygroscopic material in said smaller portion, a screen member in said larger portion resting on said shoulder and at least one additional screen member of fine mesh in said larger portion spaced from said last mentioned screen member.

WELLIAM R. MITTENDORF. 

